Remova a barra final com .htaccess

<IfModule mod_rewrite.c>
RewriteEngine On

RewriteBase /


# where the magic is done !

RewriteRule (.*)/$ $1 [R=301,L]


RewriteCond %{REQUEST_FILENAME} !-d

RewriteCond %{REQUEST_FILENAME} !-f

RewriteRule ^(.*)$ index.php?url=$1 [PT,L]

</IfModule>